Papers by Keyword: Workability

Abstract: This study evaluated the combined effect of recycled glass powder (RGP) and nanosilica on the fresh-state properties of concrete. Mixtures were prepared with partial cement replacements of 10%, 15%, and 20%, incorporating nanosilica at 1.5 % by cement weight. The control mixture (RGP-0) does not include nanosilica, allowing comparison with the additive-containing mixtures. Results showed that RGP-10 improved workability, achieving a slump of 22.6 cm compared to 7.0 cm for RGP-0, while RGP-15 and RGP-20 exhibited only slight reductions in fluidity. Air content decreased in RGP-10, RGP-15, and RGP-20, with values of 1.6 %, 1.9 %, and 1.7 %, respectively, compared to 2.3 % in RGP-0, indicating that the mixtures with RGP and nanosilica develop a denser matrix with reduced void formation. Additionally, nanosilica accelerated early hydration, raising the initial temperature by up to 3.5 °C in RGP-20 without affecting workability. These findings demonstrate that moderate cement replacement with RGP and nanosilica can produce more stable, homogeneous, and sustainable concretes, providing useful insights for designing mixtures with improved fresh state performance.

Abstract: This research project focuses on the experimental investigation of using zeolite as a partial replacement for cement in M25 grade concrete. Zeolite, a naturally occurring mineral with pozzolanic properties, has gained attention as a sustainable alternative to cement in concrete production. The study aims to assess the effects of incorporating zeolite on the properties of M25 concrete, such as compressive strength, durability, and workability. Through a series of laboratory tests and analysis, the project intends to evaluate the feasibility and effectiveness of utilizing zeolite in reducing cement content while maintaining the required performance standards of M25 concrete. The findings of this research could contribute to promoting eco-friendly practices in the construction industry by reducing the environmental impact of cement production.

Abstract: The purpose of this study is to investigate the influence of variations in the alkali activator to binder ratio (Al/Bi) on the workability, density, and compressive strength of geopolymer mortar. This study used an experimental approach to assess mortar compressive strength and workability utilizing a flow table in accordance with SNI 03-6825-2002, as well as mortar density in accordance with SNI 1973-2016. Variations in the Al/Bi ratio used are 0.40, 0.45, 0.50, and 0.55, with a slag content of 20% and a ratio of sodium silicate to sodium hydroxide (SS/SH) 1.5. The materials used in this research are fly ash type F, slag, fine aggregate, and an alkali activator consisting of sodium hydroxide (SH) and sodium silicate (SS). The specimen is in the shape of a cube with dimensions of 50x50x50 mm and a total of 16 test objects. The results show that the higher the Al/Bi ratio, the workability of the geopolymer mortar increases, but the density decreases. The higher the Al/Bi ratio, the compressive strength of the geopolymer mortar increases to an optimal Al/Bi ratio of 0.50. At an Al/Bi ratio of 0.40, it has workability in accordance with SNI 03-6825-2002 standards. All variations of the Al/Bi ratio produce density that meets the SNI 1973-2016 standards. The maximum compressive strength of the geopolymer mortar was 12.15 MPa at an Al/Bi ratio of 0.50.

Abstract: This study involves the investigation of influence of magnetic water on the workability and compressive strength of fresh and hardened concrete. “The water is initially magnetized with the help of 0.5 hp motor having a 1 and 3T magnets at its inlet pipe. Concrete samples are then prepared and cured with magnetic water and normal water in four main different cases. About 36 concrete and mortar cubes are casted and tested for 7, 14 and 28 days.” Results show that the compressive strength of concrete samples mixed with magnetic water is higher than those prepared with normal water. The compressive strength of concrete samples mixed with magnetic water at a magnetic strength of 1T increases by 10-20% more than that of normal water”. Also, the consistency of fresh concrete is improved in case of magnetic water than that of normal water.

Abstract: In structural columns, honeycombs are very common in small and big works. This problem is caused by poor consolidation of the concrete that increases the probability of honeycombs (voids left in concrete). These imply costs incurred and affect the work schedule. An exhaustive search is carried out regarding methods in the scientific literature and materials with respect to their availability in the market related to the problem. In this way, it was found that the design of a self-compacting concrete using the ACI 237R-07 with the use of a supplementary cementitious material aims to be a solution to this problem. Rice husk ashes contain silicon oxide and aluminates. These elements improve or increase the strength of the concrete, offer workability and fluidity properties. It was found that with a 5% replacement, 735 mm and 730 mm of slump flow and J-ring were obtained, respectively. Additionally, the V-funnel time was 9.58 seconds. The use of RHA positively increased the values of the measured tests with respect to the standard, thereby improving the workability and stability properties.

Abstract: Self-compacting concrete (SCC) is a concrete which flows under its own weight in the congested areas without any external force. Increase in demand and decrease in availability of fine aggregates, we use an alternative material called quarry dust, it is a finer material generated from stone quarries. This paper deals with the feasibility study on the utilization of quarry dust as a partial replacement in fine aggregate. In this experimental investigation, the properties of materials are tested as per Indian standards. The filling ability, passing ability and flowability characteristics of SCC as a partial replacement of fine aggregate with quarry dust was investigated as per EFNARC guidelines. In this experimental investigation, different mixes were prepared as a partial replacement of fine aggregate with quarry dust at various percentages such as 10%, 20%, 30%, 40% and 50% to obtain the optimum replacement level. The Slump flow, U-box, L-Box, V-Funnel and J-ring tests were carried out to determine the workability of SCC. The finding shows that the workability decreases with the addition of quarry dust. It is concluded that addition of quarry dust reduces the fresh properties of the SCC.

Abstract: Due to the shortcomings of waste bricks, they cannot be used repeatedly. The brick powder can partially replace cement for construction production, which can solve the problem of cement energy consumption. This paper studies the influence of brick powder on the performance of cement-based materials. The research shows that the water absorption effect of brick powder and the friction force are the two main factors affecting concrete. Energy dispersive spectrometer, inductively coupled plasma mass spectrometry and compressive strength tests show that the addition of brick powder leads to the increase of silicon/calcium. inductively coupled plasma mass spectrometry shows that although brick powder dissolves in the early stage, the volcanic ash effect is weak. The results of mercury intrusion porosimetry and ultrasonic pulse velocity are consistent with the compressive strength. When 5 % is added, it shows excellent durability. In addition, with the increase of age, the durability will not decrease significantly. Since the brick powder only needs to be ground to avoid the related process of cement, good economic and environmental benefits can be obtained with the increase of substitution rate.

Abstract: The continuous construction activity increases the demand for concrete production. At the same time, the construction and demolition activity also generate solid waste which is disposed of at landfills. The approach of discarding waste such as concrete waste, brick waste, and timber waste pollutes the environment. Thus, the present research investigates the effect of integrating local clay brick waste as a partial fine aggregate replacement on the properties of concrete. Several concrete mixes were prepared by integrating various percentages of crushed clay brick ranging from 0%, 5%, 10%, 15% and 20% as partial sand replacement in concrete. All specimens were subjected to continuous water curing until the testing date which is 7 days and 28 days. The finding shows that the use of up to 10% crushed clay brick successfully enhances the compressive strength of concrete. The water absorption of concrete increase as larger content of crushed clay brick waste is integrated in the mix. Basically, the use of clay brick waste in concrete would help to reduce dependency on river sand supply for concrete manufacturing and promote a cleaner environment.

Abstract: The construction industry relies heavily on concrete for its operations in the development of houses and other infrastructural facilities due to its structural stability and strength. To fulfil the requirement of concrete materials, this study focuses on investigating the use of marble powder as admixture in concrete production and its effect on the fresh and hardened properties of concrete. About 72 samples of concrete were prepared using marble powder admixture in four separate mixes by adding marble dust with the range from 0% to 6% at an incremental rate of 2wt.% of cement. The workability of the concrete mix with marble waste admixture was found to be higher than that of the control mix. The maximum compressive strength increases with the 4% marble powder admixture after 28 days and it equal to 24.50%, as compared with control mix and the flexural strength also shows a maximum increment in strength with 4% of marble powder after 28 days, which is 5.59% as compared with control mix. The density of concrete increases from 2.14 to 2.82 gm. /cm³ with the increase in admixture from 0% to 4%, on other hand with 6% marble waste the density slightly decreases when compared with the result obtained from 4% marble waste admixture. Therefore, using marble powder as an admixture up to 4% in concrete production gives excellent results in compressive strength, flexural strength, and density compared to the control mixes of concrete.

Abstract: This paper aims to evaluate mechanical behavior (compressive and flexural strength) of reactive powder concrete (RPC) with ferronickel slag (FNS) as quartz sand replacement. Standard laboratory tests were performed i.e. sieve analysis to determine the particle size distribution of the FNS, slump and density tests as well as compressive and flexural tests on the RPC. Promising results were obtained in this study. An increased consistency and density were observed upon increasing the FNS content. The utilization of FNS could lead to a compressive strength value of 86 MPa at 28 days. A higher strength enhancement in the early curing days (7 days) was observed than in the longer curing days (28 days), when FNS mixes were compared to reference mixes. The flexural strength result demonstrated two different phenomena at two different ages, where there was a slight rise at 7 days and relatively no increment at 28 days when FNS mixes were compared to the reference mixture.